I'm not sure that "for very small people" really describes the piece well, given the large stretch at the end of bar 4. Or maybe, like Stravinsky, he forgot that small people have small left hands as well as right hands.
Another solution - a very small child plays the upper part, and a slightly more advanced one the lower part, using two hands. So whether it's "for two pianists" or "very small people" becomes irrelevant.